Polymers of polymerizable polydiene ethylenically unsaturated esters

ABSTRACT

POLYMERIZABLE POLYDIENE ETHYLENICALLY-UNSATURATED ESTERS HAVING AT LEAST ABOUT ONE TERMINAL, ETHYLENICALLYUNSATURATED ACYLOXY GROUP ARE OBTAINED BY ESTERIFYING CERTAIN INTERMEDIATE POLYHYDROXY POLYMERS WITH AN ACYL COMPOUND, REACTIVE WITH HYDROXYL TO FORM AN ESTER, AND HAVING ITS ACYL GROUP ETHYLENICALLY-UNSATURATED, SUCH AS ACRYLIC, CROTONIC OR METHACRYLIC ACID. THE USUALLY LIQUID INTERMEDIATE POLYHYDROXY POLYMER HAS AN AVERAGE OF AT LEAST ABOUT 1.8 PREDOMINANTLY PRIMARY, TERMINAL, ALLYLIC HYDROXYL GROUPS PER MOLECULE AND IS AN ADDITION POLYMER CONTAINING 0 TO ABOUT 75% BY WEIGHT OF THE RESIDUE OF AN ALPHA-MONOOLEFIN, SUCH AS STYRENE, AND 25 TO 100% OF THE RESIDUE OF A 1,3-DIENE, SUCH AS BUTADIENE, THE INTERMEDIATE POLYHYDROXY POLYMER HAVING A VISCOSITY AT 30* C. OF ABOUT 5-20,000 POISES, HAVING THE MAJORITY OF ITS UNSATURATION IN THE MAIN CARBON DHAIN, AND A NUMBER AVERAGE MOLECULAR WEIGHT OF ABOUT 400 TO 25000. THESE USUALLY LIQUID POLYDIENE ETHYLENICALLY-UNSATURATED ESTERS CONTAIN TERMINAL, ALLYLIC, ETHYLENICALLY UNSATURATED ACYLOXY OR ESTER GROUPS AND ARE CAPABLE OF FURTHER POLYMERIZATION THROUGH THESE UNSATURATED END GROUPS TO PRODUCE HOMOPOLYMERS AND COPOLYMERS WITH POLYMERIZABLE VINYL MONOMERS, SUCH AS STYRENE, RANGING IN PROPERTIES FROM SOFT RUBBERS TO HIGH IMPACT PLASTICS. THESE ETHYLENICALLY-UNSATURATED ESTERS CAN BE USED AS MODIFIERS IN VARIOUS PLASTIC AND OTHER POLY-ESTER COMPOSITIONS TO IMPROVE FLEXIBLILITY, ELECTRICAL PROPERTIES AND HYDROLYTIC STABILITY.

United States Patent US. Cl. 260-86.1 14 Claims ABSTRACT OF THEDISCLOSURE Polymerizable polydiene ethylenically-unsaturated estershaving at least about one terminal, ethylenicallyunsaturated acyloxygroup are obtained by esterifying certain intermediate polyhydroxypolymers with an acyl compound, reactive with hydroxyl to form an ester,and having its acyl group ethylenically-unsaturated, such as acrylic,crotonic or methacrylic acid. The usually liquid intermediatepolyhydroxy polymer has an average of at least about 1.8 predominantlyprimary, terminal, allylic hydroxyl groups per molecule and is anaddition polymer containing 0 to about 75% by weight of the residue ofan alpha-monoolefin, such as styrene, and 25 to 100% of the residue of a1,3-diene, such as butadiene, the intermediate polyhydroxy polymerhaving a viscosity at 30 C. of about -20,000 poises, having the majorityof its unsaturation in the main carbon chain, and a number averagemolecular weight of about 400 to 25,000. These usually liquid polydieneethylenically-unsaturated esters contain terminal, allylic,ethylenically unsaturated acyloxy or ester groups and are capable offurther polymerization through these unsaturated end groups to producehomopolymers and copolymers with polymerizable vinyl monomers, such asstyrene, ranging in properties from soft rubbers to high impactplastics. These ethylenically-unsaturated esters can be used asmodifiers in various plastic and other poly-ester compositions toimprove flexibility, electrical properties and hydrolytic stability.

This invention relates to polymerizable unsaturated esters and tohomopolymers and copolymers thereof. More particularly, this inventionrelates to ethylenicallyunsaturated esters of hydroXyl-terminatedpolydiene resins, to homopolymers and copolymers thereof and to plasticand polyester compositions containing these ethylenically-unsaturatedesters and polymers thereof. It has been found in accordance with thisinvention that certain, usually liquid, intermediate polyhydroxypolymers having an average of at least about 1.8 predominantly primary,terminal, allylic hydroxyl groups per molecule can be esterified with anacyl compound, reactive with hydroxyl to form an ester, and having itsacyl group ethylenically unsaturated, such as ethylenically-unsaturatedacids, to form usually liquid, polymerizable polydieneethylenically-unsaturated esters having an average of at least one andusually at least about 1.8 or about 2 or more, terminal, allylic,ethylenically-unsaturated acylOXy groups, preferably of 3 to about 12carbon atoms, such as acrylyloxy, crotonyloxy and methacrylyloxy groups.These usually liquid polydiene ethylenically-unsaturated esters can befurther polymerized through the ethylenically-unsaturated acyloxy groupto produce homopolymers and copolymers with polymerizable vinylmonomers, such as styrene, ranging in properties from soft rubbers tohigh impact plastics.

The intermediate polyhydroxy polymers have an average of at least about1.8 predominantly primary, terminal, allylic hydroxyl groups permolecule and are an addition polymer containing 0 to about 75% by weightof the 3,652,520 Patented Mar. 28, 1972 residue of an alpha-monoolefinof 2 to about 12 carbon atoms and about 25 to of the residue of a1,3-diene of 4 to about 12 carbon atoms, the intermediate polyhydroxypolymer having a viscosity at 30 C. of about 5-20,000 poises, having themajority of its unsaturation in the main carbon chain, and a numberaverage molecular Weight of about 400 to 25,000. The intermediate polyhydroxy polymers used in this invention are particularhydroxyl-terminated polymers and copolymers of dienes with otherreactive monomers and can be prepared by the hydrogenperoxide-isopropanol mutual solvent process described hereinafter. Inaddition, suitable derivatives derived therefrom are also applicableprovided the alcohol moiety of the polymer with its primary, terminal,allylic structure remains intact. These include partially hydrogenatedor halogenated hydroxyl-terminated polybutadiene resins having themajority of its unsaturation in the main carbon chain.

The intermediate polyhydroxy polymer has a particular structure andcontains allylic hydroxyl groups, which usually are at the ends of themain, that is the longest, hydrocarbon chain of these usually liquiddiene polymers. These intermediate polyhydroxy polymers differ from thehomopolymers and copolymers of butadiene and related dienes which arecommercially available as GR-S rubber, etc. The intermediate polyhydroxypolymers may, in general, have a viscosity at 30 C., of about 5-20,000poises, preferably about 15 to 5000 poises. Often the intermediatepolymer, when a homopolymer, is obtained in a viscosity range of about20 to 300 or up to about 550 poises at 30 C. Preferably, theintermediate polyhydroxy polymers have a viscosity of about 35 to 60 orup to about to 260 poises. Thus, the intermediate polyhydroxy polymersare liquids or semi-solids flowable, at least when subjected to moderatepressure, at ambient temperatures or at temperatures up to about 400 F.The allylic hydroxy-terminated intermediate polymers used in the presentinvention will have molecular weights in the range of about 400 to about25,000 as determined by cryoscopic ebullioscopic or osomometric methods.The preferred hydroXyl-containing diene polymers 'will be in themolecular weight range of about 900 to 10,000. In contrast, conventionaldiene polymers such as GR-S rubber are extremely high in molecularweight, e.g., in the range of several hundred thousand. I

The hydroxy-terminated diene intermediate polymers employed to make thenovel compositions of this invention differ from diene polymers known totbe telechelic and/ or hydroxy-containing in that the majority ofunsaturation in the former is in the main hydrocarbon chain and in thatthe hydroxy components are in predominantly terminal positions on themain hydrocarbon chain and are predominantly primary and allylic inconfiguration. Ordinarily, at least about 1.8, often at least about 2,frequently 2.1 to 2.8 and up to about 3 or more hydroxyl groups arepresent on the average per intermediate polymer molecule. Since thesehydroxyl groups are predominantly primary, terminal and allylic instructure, with approximately two of the hydroxyl groups being atterminating positions on the main carbon chain, the polymers are highlyreactive. The intermediate polyhydroxy polymer has the majority of itsunsaturation in the main hydrocarbon chain and this appears to providepolymers of improved elasticity characteristics.

The dienes which are employed to make the intermediate polymers includethe unsubstituted, Z-substituted or 2,3-disubstituted 1,3-dienes or 4 upto about 12 carbon atoms. The diene preferably has up to 6 carbon atomsand the substituents in the 2- and/or 3-position may be hydrogen, alkyl,generally lower alkyl, e.g. of 1 to 4 carbon atoms, aryl (substituted orunsubstituted), halogen, nitro, nitrile, etc. Typical dienes which maybe employed are 1,3-butadiene, isoprene, chloroprene,2-cyano-1,3-butadiene, 2,3-dimethyl-1,3-butadiene,2-phenyl-1,3-butadiene, 2-methyl-3-phenyl-1,3-butadiene, etc. The choiceof diene will usually depend upon properties desired in the finalelastomer, for example, chloroprene may be used, alone or in admixturewith other dienes to produce oilresistant and fiameproof rubbers.

Although intermediate polymers of the above described type, averagingmore than one predominantly primary hydroxyl per molecule, say about 1.8to 3 or more per molecule, may be employed in this invention, theypreferably have an average of at least 2 or about 2.1 to 2.4 up to 2.8hydroxyl groups per molecule and the hydroxyl groups are predominantlyin terminal, allylic positions on the main, generally longest,hydrocarbon chain of the molecule. By allylic configuration is meant thealpha-allylic grouping of allylic alcohol, that is the terminalhydroxyls of the intermediate polymer are attached to a carbon adjacentto a double-bond carbon. Preferably, the polymer is substantially freeof other hydroxyl groups in order to avoid indiscriminate, premature orexcessive cross-linking.

The ratio of cis-1,4 and trans-1,4 and 1,2-vinyl unsaturation whichoccurs in the diene polymers used in the present invention, the numberand location of the hydroxyl groups and the molecular weight of theintermediate polymers can be a function of polymerization temperatureand the type of addition polymerization system employed in forming thepolymer. It has been found that diene polymers of the desiredconfiguration can be obtained using hydrogen peroxide as the catalystfor polymerization in a mutual alcohol solvent system. This free-radicaladdition polymerization usually takes place in solution at a temperatureof about C. to 200 C., preferably about 100-150 C.

The reaction preferably takes place in a mutual solvent system; that is,one which dissolves both the diene monomer and the hydrogen peroxide.Suitable solvents are isopropanol, methanol, sec-butanol, n-butanol,n-propanol and like saturated alcohols, preferably alkanols having 2 toabout 12 carbon atoms. The H O -solvent system is found to supplyhydroxyl groups and the catalytic and solvent effects needed to producethe intermediate diene polymers of desired chemical and physicalcharacteristics. In such a polymerization system, the alcohol serves asa solvent for the peroxide and as a solvent or diluent for the dienemonomer and is used in an amount suitable to promote adequately rapidbut controllable polymerization of the monomer material in the solutionto form the diene polymers. The alcohol will be free of any group whichwould interfere with the production of the desired diene polymer.Saturated alcohols are preferred and often those having about the samecarbon atom content as the diene monomer will be found most useful.Thus, propanol or isopropanol is often used in butadiene polymerization.The H O -alcohol system may also contain ketones, ethers,alcohol-ketones, alcohol-ethers and alcohol-esters which are miscible inwater in all proportions and which do not contain polymerizablecarbon-to-carbon unsaturation or otherwise interfere with polymerizationor enter into the product. The peroxide material may be used in amountsof about 1% to 15% of the reaction mixture to assure a low molecularweight addition polymer product having more than two hydroxyl groups permolecule.

The usable intermediate polyhydroxy polymers of butadiene will have themajority of their unsaturation in the main carbon chain and will conformto the following simplified chemical structure:

in which 11 plus p is greater than q, that is, the inchain unsaturationaccounts for more than 50% of the unsaturation. One or more of thehyclrogens appearing in the above formula may be replaced by hydroxyl insome of the molecules. This formula should not be understood as implyingthat the polymers are necessarily in blocks, but the cis-l, 4-, trans-1,4- and vinyl (1,2) unsaturation are usually distributed throughout thepolymer molecule. Generally n will be a number sufiicient to give acis-1,4-unsaturation content of about 10-30 percent; p will be a numbersufficient to give a trans-1,4-unsaturation content to the polymer inthe range of about 40-70 percent while q will be sufficient to give apendant 1,2-vinyl unsaturation of about 10-35 percent. Often the polymerwill contain largely trans-1,4-units e.g., about 50-65 percent and about15-25 percent cis-l,4-units, with about 15-25 percent l,2- uints.Branching may also occur in the above polymers, especially thoseprepared at higher temperatures. These hydroxyl terminated polybutadieneresins are usually low molecular weight liquid polymers composed mainlyof butadiene units in their backbone structure.

.Olefinically-unsaturated monomers may be incorporated into the dieneintermediate polymer products used in this invention and these may oftenbe components which provide cross-linking sites. Usable monomers includealpha-monoolefinic materials of about 2 to 3 to 10 or about 12 carbonatoms, such as styrene, vinyl toluene, methyl methacrylate,methylacrylate, acrylic esters, vinyl chloride, vinylidene chloride,etc. Acrylonitrile, acrylic acid, vinylidene cyanide, acrylamide, etc.,provide low-molecular weight hydroxy-terminated diene intermediatecopolymers which have sites suitable for crosslinking. As can be seen,the usable olefinic monomers may be ethylenes, substituted with halogen,aromatic hydrocarbon, or even cyano or carboxyl-containing radicals insome instances. The choice and amount of monoolefinic monomer employedwill often be determined on the basis of properties desired in the finalelastomer resin. For example, solvent-resistant rubbers may beformulated by copolymerization of butadiene with acrylonitrile, or othermonoolefin, substituted with a non-hydrocarbon radical, to produce theintermediate polymer. Generally the amount of monoolefinic monomer inthe polymer will be 0 to about by weight of the total addition polymer,preferably about 1 to 40% or even about 10-40%, and the balance can beessentially the 1,3 diene.

In addition to the homopolymers and copolymers comprise of single dienesand single monoolefinic or vinyl monomers, the present invention mayalso use intermediate polymers made from combinations of a plurality ofdienes and monoolefinic monomers. For example, mixtures of butadiene,isoprene and styrene can be polymerized to afford low molecular weighthydroxyl-containing interpolymers. Various combinations of dienes andmonoolefinic monomers may be copolymerized to producehydroxyl-containing copolymers or interpolymers which may be used toform elastomers. Also, the polymer materials used in this invention maybe given improved oxidation and ozone resistance by hydrogenating thehydroxyl-containing diene polymers to their corresponding morehydroxyl-containing diene polymers to their cor respondingmore-saturated derivatives. Usually, the hydroxyl-containing dienepolymers used in the present in vention will at most be only partiallyhydrogenated, so as to provide a material which is more stable due todiminished unsaturation but which still has good elastomer properties.

The main criteria for the unsaturated acid or acyl compound is that oncereacted with the hydroxyl terminated polydiene resin, the acyl compoundintroduces a reactive polymerizable double bond into the liquidpolydiene resin. One type of unsaturated acid or acyl compound which canbe used is represented by the following structure:

wherein R -H', alkyl, --C0 R', CN, halogen, or phcnyl R'=H, alkyl, oraromatic, such as phenyl, and

R" and R"'=H, alkyl, aromatic, such as phenyl, the acrylic polyester ofpolybutadiene may be depicted CO R', as follows:

-CH-CHz- OH=CH iolybutadiene or CN. 0: I Variousethylenically-unsaturated acyl compounds re- (5 active with hydroxyl toform an ester and having the acyl 0 0:

group ethylenically-unsaturated, preferably of 3 or 4 to I polybutadiene(EHCH2-CHCH2 about 12 carbon atoms, can be used. Thus there can be Iused an acrylyl or methacrylyl compound, such as acrylic Z acid, acrylylchloride or other halide, methyl acrylate, methacrylic acid, methacrylylchloride or other halide, 15 Jm=0m crosslinked polymer polybutndien andmethyl methacrylate. Crotonic acid, crotonyl halide and methyl crotonateare illustrative of other unsaturated acyl compounds which can be used.It is preferable to em- 0:

ploy an aliphatic hydrocarbon ethylenically unsaturated --lH--CH acylcompound of 3 or 4 to about 12 carbon atoms in the acyl group and whichmay have terminal ethylenic unsaturation, i.e., a terminal methylenegroup at the end of the acyl group. This affords active terminal,ethylenic unsaturation in the allylic acyloxy end groups of thepolydiene polymers thus facilitating further polymerization. Thepolydiene polymer is often fully acylated, although it can be onlypartially acylated. When the polydiene polymer is fully acylated, itwill have per molecule an Copolymers and terpolymers of liquidunsaturated esters of hydroxyl-terminated polydiene resins with otherreactive vinyl monomers can be prepared via the polymerizationtechniques described above. Included in this class of reactive vinylmonomers are styrene, acrylonitrile,

acrylate esters, methacrylate esters, acrylamides, and in generalpolymerizable vinyl monomers, preferably of 2 or 3 to about 12 carbonatoms, represented by the formula:

average number of predominantly primary, termmal, allylic,ethylenically-unsaturated acyloxy groups corre- A) sponding in number tothe predominantly primary, ter- CH2: R minal, allylic, hydroxy groupswhich were in the un- White R=aromat1c9 Such as P y CO2H, acylatedpolydiene polymer. 2 C1,

Any suitable method of esterification of the intermegdiate polyhydroxypolymer can be used to prepare the un- 0 saturated polydiene esters andpolyesters of this invention lk l or including direct esterificationwith an ethylenically-un- R'LF Cl, Br, H aromatic Such as phenyl oralkyl saturated acid, transesterification with an ethylenically-R"=I-I., lk l, or aromatic, such as phenyl. F unsaturated ester, andeSterifiCation an ethylenicallyample copolymerization of the acrylicpolyester of poly.

unsaturated acyl chloride or other halide. In addition 40 butadiene andstyrene may be depicted as f ll other suitable methods ofesterification, including use of conventional esterification catalysts,can be used to prei CH2 a 2 pare the unsaturated polydiene esters andare applicable. u C +Q-cu ca 0 I c By suitably adjusting the ratio ofmole equivalents of the I 2 ethylenically-unsaturated acyl compound tothe mole polybutadiene-9 p0 equivalents of the intermediate polyhydroxypolymer, the

mono-ester can be obtained. Usually an excess ofethylenically-unsaturated acyl compound is used to obtain the lpolyester. CH3

The reaction of polyhydroxybutadiene with acrylic acid halide can bedepicted as follows: copolymer,

I butadiene o I c 0 (unsaturated mono-ester)CHFCH-COOHZCH=CHpolybutad1ene-CH=CH-CH O-COH=CH2 II residue H 0 0(unsaturated polyester or fully acylated unsaturated ester) The homo andcopolymerization of the unsaturated Copolymers with similar propertiesto the above polyesters of hydroxyl terminated polydiene resins can beacester copolymers but which are thermoplastic are prepared complishedby known suitable polymerization techniques. from the unsaturatedmono-esters of polybutadiene resins These include free radical initiatedpolymerization using and reactive vinyl comonomers as depicted belowwith suspension, emulsion, solution, or bulk techniques, andpolybutadiene acrylate monoester and styrene. anionic inducedpolymerization methods.

The infra-red absorption spectra of the polybutadiene CH2 W3 CH Mpolyacrylate, polybutadiene polymethacrylate and polyf *Q'fi" 2 Ibutadiene polycrotonate are in agreement with the struc- 0- tures hereindisclosed. fiply butadiene oi iueadiene Polymerization of unsaturatedpolyesters of hydroxyl a,

terminated polydiene resins proceeds mainly through the t reactivedouble bonds contained in the ester moieties of The PTOPOTUOH ofunsaturated ester f he l termedlthe liquid polymers. For example,homopolymerization of ate polyhydroxy polymer to the polymerizable vinylmonomer in the copolymers can be by Weight from about 1 to 100%, andoften is about 5% to 60% up to 100%. For example, often about 55-70% ofthe unsaturated ester with about 3045% of vinyl monomer, as styrene, isused.

The unsaturated esters of polybutadiene resins can be used to modifyknown polymers via copolymerization techniques and introduce increasedflexibility and impact resistance. For example, polystyrene is known tobe a very brittle polymer having very low impact properties.Copolymerizing styrene with small amounts of unsaturated esters ofpolybutadiene resins affords flexibility and impact resistance in theresultant high styrene content copolymer.

Copolymers containing about 50% or higher unsaturated ester ofpolybutadiene resins and the remainder reactive vinyl comonomer aregenerally elastomeric in nature and can be used to advantage to preparea variety of general purpose rubbers as well as specialty rubbers. Theseelastomeric compositions can be used in the preparation of rubber goodsas well as elastomeric caulks, sealants, adhesives, missile fuelbinders, etc.

Speciality rubbers having high comonomer contents in relation topresently available rubbers are now possible. For example,nitrile-derived components in conventional nitrile rubber are limited toconcentrations of about 40%. Higher nitrile content rubbers made byconventional techniques cannot be processed. Copolymerization ofunsaturated esters of polybutadiene resins with acrylonitrile ascomonomer can be carried out to provide elastomers having anacrylonitrile-derived component up to, for instance about 50%. Thesehigh nitrile content elastomers exhibit superior solvent resistance.Other examples of rubbers which can be prepared with high comonomercontents from unsaturated esters of polybutadiene resins are highstyrene rubbers, high acrylate ester rubbers having good hightemperature and oil resistance properties, and high vinyl acetaterubbers.

The following examples are illustrative of various embodiments of thisinvention and include preferred embodiments.

EXAMPLE A Four hydroxyl-terminated polybutadiene polymers are describedas being exemplary of those which can be used in the present invention.

Polybutadiene 45 is a polyhydroxybutadiene homopolymer typically havinga viscosity of 46 poises at 30 C., a hydroxyl content of 0.84 meq./gm.,a hydroxyl number (mg. KOH/gm.) of 47, an average molecular weight of2700, about 2.3 terminal, allylic, hydroxyl groups which arepredominantly primary, and an iodine number of 395. The polymer can beprepared by polymerizing 100 parts of butadiene in the presence of 70parts of isopropanol and parts of hydrogen peroxide in an aluminum cladautoclave at 118 C. for 2 hours.

Polybutadiene is a polyhydroxybutadiene homopolymer typically having aviscosity at C. of 170 poises, a hydroxyl content of 0.71 meq./gm., ahydroxyl number (mg. KOH/gm.), of 45, an average molecular weight of3400, about 2.4 terminal, allylic, hydroxyl groups which arepredominantly primary and an iodine number of 395. This polymer can bemade by polymerizing 100 parts of butadiene 1n the presence of parts ofisopropanol and 6 parts of hydrogen peroxide for 2 /2 hours at 130 C.

Styrene-butadiene copolymer 15 typically has a molecular Weight of about3400, a viscosity at 30 C. of 225 poises, a hydroxyl content (meq./ gm.)of 0.71, a hydroxyl number of mg.KOH/gm., about 2.4 terminal, allylic,hydroxyl groups which are predominantly primary; and an iodine number of335. The copolymer is made by polymerizing parts butadiene and 25 partsstyrene in the presence of 70 parts isopropanol and 10 parts of 50%hydrogen peroxide for 2 /2 hours at 120 C.

Aerylonitrile copolymer l5 typically has a viscosity of 8 570 poises at30 C., a hydroxyl content of 0.62 meq./ gm., and hydroxyl number of 45mg. KOH/gm., an average molecular weight of 4000, about 2.5 terminal,allylic hydroxyl groups, which are predominantly primary, and an iodinenumber 345. This polymer can be made by copolymerizing acrylonitrilewith butadiene in isopropanol solvent and in the presence of hydrogenperoxide using the following ratio of reactants; parts butadiene, 15parts acrylonitrile, 70 parts isopropanol, 10% hydrogen peroxide. Thereactants are heated in an autoclave at 118 C. for 1% hours andstripped.

EXAMPLE I Preparation of polybutadiene 45 acrylatc A solution of 238 g.(0.200 equivalents) of Polybutadiene 45 and 2.77 g. of hydroquinone(1.0% of total reactants weight) was stirred in 400 ml. of benzene undera nitrogen atmosphere without heating. Then 36.21 g. (0.400 equivalents,100% excess) of acrylyl chloride was added with constant stirring overthe course of 2.0 hours. The reaction solution was then heated to49.0:0.5 C. with stirring for 160 hours.

After the reaction solution had been cooled to room temperature, it wasextracted four times with 100 ml. portions of 2.5% sodium hydroxide,followed by five extractions with 100 ml. portions of water. After beingdried over anhydrous magnesium sulfate and filtered, the solution wasplaced in a flash evaporator and the bulk of benzene removed under plantvacuum to a pot temperature of 60 C. The last traces of volatile matterwere removed under a vacuum of 0.1 mm. of mercury at a pot temperatureof 60 C.

At this point the material was a slightly cloudy, light yellow, viscousoil. Quantitative elemental analysis gave the following results: Calcd.,Carbon: 86.64%, Hydrogen 10.79%; Found: Carbon: 86.23%, Hydrogen:10.79%. An infrared analysis of this product as in excellent agree mentwith the structure for the fully acylated ester, Polybutadiene 45acrylate. As the infrared spectrum showed no absorption attributable tohydroxyl groups, this indicated that all of the hydroxyl groups had beenacylated. The yield of this material was 208 g. (83.6% yield).

EXAMPLE II Preparation of polybutadiene 45 methacrylate A mixture of 119g. of polybutadiene 45 (0.100 equivalents), 50.06 g. of methylmethacrylate (0.500 equivalents; 400% excess), and 1.71 g. ofhydroquinone (1.0% of total reactants Weight) was heated to the vicinityof C. with constant stirring. At this temperature a total of 2.0 ml. ofcatalyst (tetra-iso-propyl titanate) was added over the course of 3.0hours. The temperature of the reaction was then increased to thevicinity of 105 C. for an additional 23.0 hours. At this point theheating was discontinued and the reaction mixture was cooled to roomtemperature.

The crude reaction mixture Was stirred with ml. of benzene and 100 ml.of water. The resulting emulsion was centrifuged; the deep redsupernatant liquid was decanted, dried over anhydrous magnesium sulfate,and filtered. The bulk of the benzene and unreacted methyl methacrylatewas removed on the flash evaporator under plant vacuum to a pottemperature of 60 C. The residual volatiles were removed at a pressureof 0.1 mm. of mercury to a pot temperature of 60 C.

At this point the material was a clear, deep red, mobile liquid.Quantitative elemental analysis gave the following results: Calculated,Carbon: 86.15%, Hydrogen: 10.80%; Found, Carbon: 86.31%, Hydrogen:10.85%. An infrared absorption spectrum of a sample of this material wasin excellent agreement with the structure for the fully acylated ester,polybutadiene 45 methacrylate. The yield of this material was 119 g.(94.6% yield).

9 EXAMPLE IH Preparation of polybutadiene 45 crotonate A mixture of 50g. of polybutadiene 45 (0.0420 equivalents), 21.04 g. of methylcrotonate (0.2100 equivalents), and 0.72 g. of dibutyl tin oxide (1.0%of total weight) was heated in an oil bath to 90i1 C. for 28.0 hourswith constant stirring under a nitrogen sweep. After cooling, thereaction mixture was filtered through a fine glass filter under plantvacuum. The slightly cloudy, slightly yellow oil was then stripped ofthe excess methyl crotonate under a high vacuum (0.25 mm. Hg) at atemperature of 60 C. for two hours on a rotary evaporator. An infraredanalysis of this product showed no absorption attributable to residualhydroxyl functionality. The yield of this material, the fully acylatedester, polybutadiene 45 crotonate, was 52.85 g. (99.98% of theory).Quantitative elemental analysis gave the following results: Calc.,Carbon: 86.63%, Hydrogen: 100.83%. Found: Carbon 86.32%, Hydrogen:10.84%.

EXAMPLE IV Homopolymer of polybutadiene 45 acrylate The liquidpolybutadiene 45 acrylate of Example I was homopolymerized in bulk with1.0 weight percent benzoyl peroxide at 80% C. for 24 hours. Theresulting homopolymer was a rubber.

EXAMPLE V Polybutadiene 45 acrylate-styrene copolymers These monomers,polybutadiene 45 acrylate prepared as in Example I and styrene, werecopolymerized at various monomer ratios using the following method.Weighed amounts of the comonomers were placed in a polymerization vesselalong with 2.0% benzoyl peroxide (by weight on total monomers). Theresulting solution was stirred at 80 C. until a pourable near gel wasobtained. At this point the reaction contents were poured into a 6" x 6"x /s" mold and allowed to react at 80 C. for 16 hours.

The resulting copolymer castings were used to prepare standard testspecimens.

Polymerization of unsaturated esters of hydroxyl-terminatedpolybutadiene resins either by themselves or with other comonomers asherein described results in mate rials which vary from soft rubbers tohigh impact plastics. These materials are not thermoplastic and arecrosslinked due to the presence of 2+ unsaturated ester moieties on thepolybutadiene resins.

Table I shows the physical properties of copolymers prepared from theacrylate ester of polybutadiene 45 and styrene. As the styrene contentincreased the copolymers produced transformed from soft rubbers toelastoplastics and finally, into materials similar in properties to highimpact styrene.

TABLE I.STYRENE-POLYBUTADIENE 45 AORYLATE C O P O L YME R S Test A B CMonomer composition, wt. percent:

Polybutadiene 45 acrylate 50 33 20 Styrene 50 67 80 Properties ofcopolymer:

Tensile strength, p.s.i 718 3, 200 2, 700 100% modulus, p.s.i 320 1, 3201, 770

Tear strength, p.l.i 37 270 480 Percent elongation. 160 210 180 Shore AHardness 63 92 95 Melting point Appearance Clear Clear ClearClassification 1 Does not; melt below 300 C. B Elastomer. Elastoplastic.

Products made from 90% to 95% or more of styrene and up to about ofpolybutadiene 45 acrylate copolymer are thermoplastic and can beremolded under 10 pressure at temperatures of about 120-150 C. As can beseen from the foregoing data polyacrylate esters of polybutadiene resinsare effective monomers for crosslinking and introducing flexibility andimpact resistance into styrene polymers.

The 50% styrene copolymer is a crosslinked elastomeric material whichcan be carbon black reinforced and oil extended. It has excellentelectrical properties, good abrasion resistance and excellent lowtemperature properties. This elastomer when properly compounded withreinforcing aids can be used in the preparation of a variety of liquidcastable rubber articles including rubber wheels, gears, bushings,rollers, and solid and pneumatic tires. Numerous additional advantagescan be listed for the styrene copolymers, which include a liquidcastable monomer system and a room temperature peroxide cure system.

EXAMPLE VI Polybutadiene 45 acrylate methyl methacrylate copolymersOther plastic materials which can be modified by unsaturated esters ofpolybutadiene resins include polymet hacrylate and polyester plastics.For example, copolymerization of methyl methacrylate with 530%polybutadiene 45 polyacrylate resulted in materials having increasedflexibility and scratch resistance when compared with unmodifiedpoly(methylmethacrylate).

A solution of 35.00 g. of Polybutadiene 45 acrylate as prepared inExample I, 140.00 g. of methyl methacrylate, and 1.75 g. of benzoylperoxide was prepared by stirring these materials at 60 C. for aboutfive minutes. The total reactants charge of 175.00 g. was composed of80.0% methyl methacrylate and 20.0% polybutadiene polyacrylate; thebenzoyl peroxide was present at 1.0% of the total reactants charge. Thissolution was poured into the standard vertical mold, previouslydescribed. The mold was placed into the oven and held at 130 F. for 88hours. Upon cooling and demolding, the homogeneous casting possessedmore flexibility than a similar casting, prepared without thepolybutadiene polyacrylate.

EXAMPLE VII Copolymers of 5% polybutadiene 45 acrylate and styrene Asolution of 7.50 g. of Polybutadiene 45 acrylate prepared as in ExampleI, 142.50 g. of styrene, and 1.50 g. of benzoyl peroxide was prepared bystirring these materials at 60 C. for about ten minutes. The totalreactants charge of 150.00 g. was composed of 95.0% styrene and 5.0%polybutadiene acrylate, by weight; the benzoyl peroxide was present at1.0% of the total reactants charge. This solution was poured into avertical 10" x 10 cavity produced by a 4;" spacer of suitable dimensionsclamped between two 30 gauge stainless steel sheets, backed by /2" thickplywood forms. This mold was then placed into an oven, thermostaticallycontrolled at 130:2 F. for 88 hours. A fluorocarbon mold release agentWas employed, which had been previously baked onto the steel plates. Theresulting homogeneous semiflexible plastic casting displayed theproperties of a high impact plastic. Pieces of this plastic materialcould be remolded into a homogeneous sheet in a standard 5" x 5" xcompression mold by heating at 150 C. for one-half to two hours underpressure.

The crotonate and methacrylate esters of Polybutadiene 45 havingunsaturated acyl moieties can be homopolyrnerized and copolymerized withvinyl monomers in the same manner as the acrylate esters ofPolybutadiene 45 to give products varying in properties from highlyflexible elastomers through semi-flexible elastoplastics to strong,high-impact plastics.

If desired, additional materials, such as extenders and finely dividedsolid fillers can be incorporated, especially 11 prior topolymerization, in the polymers and copolymers of this invention. Someconventional fillers are carbon black, asphaltenes, silica,silica-alumina, hydrated silica, zinc oxide, magnesium carbonate, clays,talc, and pulverized reclaimed rubber as well as other various mineralreinforcing or inert fillers which are known in the art. Solid fillersmay be employed, if desired, in the amount of -100 or more parts per 100parts of polymers in the final product, and when used in significantamounts usually at least about is employed, based on the polymers.

It is claimed:

1. The addition homopolymers ranging in physical state from soft rubbersto high impact plastics, of polymerizable polydieneethylenically-unsaturated ester containing per molecule an average ofabout 1.8 to 3 terminal, allylic positioned, ethylenically unsaturatedacyloxy groups of 3 to about 12 carbon atoms and being theesterification product of an intermediate polyhydroxy polymer and anethylenically-unsaturated acyl compound, said acyl compound beingreactive with hydroxyl to form an ester, having its acyl groupethylenically-unsaturated and having 3 to about 12 carbon atoms, andsaid intermediate polyhydroxy polymer having an average of about 1.8 to3 predominantly primary, terminal, allylic hydroxyl groups per moleculeand being a free radical hydrogen peroxide catalyzed addition polymercontaining 0 to about 75% by weight of an alpha monoolefin of 2 to about12 carbon atoms, and about to 100% of a 1,3-diene of 4 to about 12carbon atoms, said intermediate polyhydroxy polymer having a viscosityat C. of about 520,000 poises, having the majority of its unsaturationin the main carbon chain, and a number average molecular weight of about400 to 25,000.

2. The addition copolymers ranging in physical state from soft rubbersto high impact plastics, of polymerizable polydieneethylenically-unsaturated ester and polymerizable vinyl monomer of 2 toabout 12 carbon atoms, said polymerizable polydieneethylenically-unsaturated ester containing per molecule an average ofabout 1.8 to 3 terminal, allylic-positioned, ethylenically-unsaturatedacyloxy groups of 3 to about 12 carbon atoms and being theesterification product of an intermediate polyhydroxy polymer and anethylenically-unsaturated acyl compound, said acyl compound beingreactive with hydroxyl to form an ester, having its acyl groupethylenically-unsaturated and having 3 to about 12 carbon atoms, andsaid intermediate polyhydroxy polymer having an average of about 1.8 to3 predominantly primary, terminal, allylic hydroxyl groups per moleculeand being a free radical hydrogen peroxide catalyzed addition polymercontaining 0 to about 75 by weight of an alpha monoolefin of 2 to about12 carbon atoms, and about 25 to 100% of a 1,3-diene of 4 to about 12carbon atoms, said intermediate polyhydroxy polymer having a viscosityat 30 C. of about 5-20,000 poises, having the majority of itsunsaturation in the main carbon chain, and a number average molecularweight of about 400 to 25,000.

3. The addition homopolymers ranging in physical state from soft rubbersto high impact plastics, of polymerizable polydieneethylenically-unsaturated ester containing per molecule an average ofabout 2.1 to 2.8 terminal, allylic-positioned, ethylenically-unsaturatedacyloxy groups of 3 to about 12 carbon atoms and being theesterification product of an intermediate polyhydroxy polymer and anethylenically-unsaturated acyl compound, said acyl compound beingreactive with hydroxyl to form an ester, having its acyl groupethylenically-unsaturated and having 3 to about 12 carbon atoms, andsaid intermediate polyhydroxy polymer having an average of about 2.1 to2.8 predominantly primary, terminal, allylic hydroxyl groups permolecule and being a free radical hydrogen peroxide catalyzed additionpolymer of a 1,3-diene hydrocarbon of 4 to 12 carbon atoms, saidintermediate polyhydroxy polymer having a viscosity at 30 C. of about520,000 poises, having the majority of its unsaturation in 12 the maincarbon chain, and a number average molecular weight of about 400 to25,000.

4. The addition copolymers ranging in physical state from soft rubbersto high impact plastics, of polymerizable polydieneethylenically-unsaturated ester and polymerizable vinyl monomer of 2 toabout 12 carbon atoms, said polymerizable polydieneethylenically-unsaturated ester containing per molecule an average ofabout 2.1 to 2.8 terminal, allylic-positioned, ethylenically-unsaturatedacyloxy groups of 3 to about 12 carbon atoms and being theesterification product of an intermediate polyhydroxy polymer and anethylenically-unsaturated acyl compound, said acyl compound beingreactive with hydroxy to form an ester, having its acyl groupethylenically-unsaturated and having 3 to about 12 carbon atoms, andsaid intermediate polyhydroxy polymer having an average of about 2.1 to2.8 predominantly primary, terminal, allylic hyhydroxyl groups permolecule and being a free radical hydrogen peroxide catalyzed additionpolymer of a 1,3- diene hydrocarbon of 4 to about 12 carbon atoms, saidintermediate polyhydroxy polymer having a viscosity at 30 C. of about520,000 poises, having the majority of its unsaturation in the maincarbon chain, and a number average molecular weight of about 400 to25,000.

5. The homopolymers of claim 3 wherein said 1,3-diene hydrocarbon isbutadiene.

6. The copolymers of claim 4 wherein said 1,3-diene hydrocarbon isbutadiene.

7. The homopolymers of claim 3 wherein said terminal,ethylenically-unsaturated acyloxy groups are acrylyloxy groups and saidethylenically-unsaturated acyl compound is an acrylyl compound reactivewith hydroxyl to form the acrylic ester.

8. The copolymers of claim 4 wherein said terminal,ethylenically-unsaturated acyloxy groups are acrylyloxy groups and saidethylenically-unsaturated acyl compound is an acrylyl compound reactivewith hydroxyl to form the acrylic ester.

9. The homopolymers of claim 3 wherein said terminal,ethylenically-unsaturated acyloxy groups are methacrylyloxy groups andsaid ethylenically-unsaturated acyl compound is a methacrylyl compoundreactive with hydroxyl to form the methacrylic ester.

10. The copolymers of claim 4 wherein said terminal,ethylenically-unsaturated acyloxy groups are methacrylyloxy groups andsaid ethylenically-unsaturated acyl compound is a methacrylyl compoundreactive with hydroxyl to form the methacrylic ester.

11. The addition homopolymers ranging in physical state from softrubbers to high impact plastics, of liquid polymerizable polydieneethylenically-unsaturated ester containing per molecule an average ofabout 2.1 to 2.8 terminal, allylic-positioned, ethylenically-unsaturatedacyloxy group selected from the the group consisting of acrylyloxy,crotonyloxy and methacrylyloxy groups, and being the esterificationproduct of a liquid intermediate polyhydroxy polymer and anethylenically-unsaturated acyl compound selected from the groupconsisting of acrylyl, crotonyl and methacrylyl compounds, said acylcompound being reactive with hydroxyl to form an ester, and said liquidintermediate polyhydroxy polymer having an average of about 2.1 to 2.8predominantly primary, terminal, allylic hydroxyl groups per moleculeand being a free radical hydrogen peroxide catalyzed addition polymer of1,3-butadiene, said intermediate polyhydroxy polymer having a viscosityat 30 C. of about 15 to 5000 poises, having the majority of itsunsaturation in the main carbon chain, and a number average molecularweight of about 900 to 10,000.

12. The addition copolymers ranging in physical state from soft rubbersto high impact plastics, of liquid polymerizable polydieneethylenically-unsaturated ester and polymerizable vinyl monomer of 2 toabout 12 carbon atoms, said polymerizable polydieneethylenically-unsaturated ester containing per molecule an average ofabout 2.1 to 2.8 terminal, allylic-positioned, ethylenically-unsaturatedacyloxy groups selected from the group consisting of acrylyloxy,crotonyloxy and methacrylyloxy groups, and being the esterificationproduct of a liquid intermediate polyhydroxy polymer and anethylenically-unsaturated acyl compound selected from the groupconsisting of acrylyl, crotonyl and methacrylyl compounds, said acylcompound being reactive with hydroxyl to form an ester, and said liquidintermediate polyhydroxy polymer having an average of about 2.1 to 2.8predominantly primary, terminal, allylic hydroxyl groups per moleculeand being a free radical hydrogen peroxide catalyzed addition poly- Inerof 1,3-butadiene, said intermediate polyhydroxy polymer having aviscosity at 30 C. of about 15 to 5000 poises, having the majority ofits unsaturation in the main carbon chain, and a number averagemolecular weight of about 900 to 10,000.

13. A copolymer of claim 12 wherein said vinyl monomer is styrene.

14. A copolymer of claim 12 wherein said vinyl monomer is methylmethacrylate.

References Cited UNITED STATES PATENTS FOREIGN PATENTS France.

JAMES A. SEIDLECK, Primary Examiner U.S. Cl. X.R.

